American Academy of Microbiology

Education Resources

Laboratory Protocols

Laboratory Protocols are information briefs about standard laboratory tests and include the procedural steps as well as the purpose, theory, history, safety considerations, tips and comments, and references. The protocols are geared for microbiology educators at all levels and assume a basic understanding of general microbiology. All protocols are free, original, open access, and peer-reviewed by the microbiology educator community. Protocols were published between 2005 and 2015.

Phenylethyl alcohol agar (PEA) is a selective medium that permits the growth of gram-positive cocci while inhibiting most gram-negative organisms. PEA agar is used for the isolation of gram-positive Staphylococcus species and Streptococcus species from clinical specimens or specimens that contain mixtures of bacterial flora.